skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Electronic structure and disorder in Na xCoO 2 and SrRh 2O 4

Abstract

We discuss the electronic structure of NaxCoO2 from the point of view of first principles electronic structure calculations. The band structure contains low spin Co ions, with average charge 5+x leading to a nearly full Co t2g manifold. The bands corresponding to this manifold are narrow and separated from the O 2p bands and from the eg bands, which are also narrow. There are two main sheets of Fermi surface, a large section derived from ag symmetry states, and small hole pockets. We find significant effects due to Na disorder on these small sections, with the result that they should be localized. This is discussed in relation to recent photoemission experiments. For comparison, we present a virtual crystal band structure of beta-SrRh2O4. Like NaxCoO2 it shows a large crystal field gap between narrow t2g and eg manifolds, but because of its stoichiometry is a semiconductor rather than a high carrier density metal.

Authors:
 [1];  [1];  [2]
  1. ORNL
  2. Central Michigan University, Mt. Pleasant
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
968234
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Solid State Sciences; Journal Volume: 9
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SODIUM OXIDES; COBALT OXIDES; STRONTIUM OXIDES; RHODIUM OXIDES; ELECTRONIC STRUCTURE; FERMI LEVEL; ORDER PARAMETERS

Citation Formats

Singh, David J, Kasinathan, Deepa, and Fornari, M. Electronic structure and disorder in NaxCoO2 and SrRh2O4. United States: N. p., 2007. Web. doi:10.1016/j.solidstatesciences.2007.03.008.
Singh, David J, Kasinathan, Deepa, & Fornari, M. Electronic structure and disorder in NaxCoO2 and SrRh2O4. United States. doi:10.1016/j.solidstatesciences.2007.03.008.
Singh, David J, Kasinathan, Deepa, and Fornari, M. Mon . "Electronic structure and disorder in NaxCoO2 and SrRh2O4". United States. doi:10.1016/j.solidstatesciences.2007.03.008.
@article{osti_968234,
title = {Electronic structure and disorder in NaxCoO2 and SrRh2O4},
author = {Singh, David J and Kasinathan, Deepa and Fornari, M.},
abstractNote = {We discuss the electronic structure of NaxCoO2 from the point of view of first principles electronic structure calculations. The band structure contains low spin Co ions, with average charge 5+x leading to a nearly full Co t2g manifold. The bands corresponding to this manifold are narrow and separated from the O 2p bands and from the eg bands, which are also narrow. There are two main sheets of Fermi surface, a large section derived from ag symmetry states, and small hole pockets. We find significant effects due to Na disorder on these small sections, with the result that they should be localized. This is discussed in relation to recent photoemission experiments. For comparison, we present a virtual crystal band structure of beta-SrRh2O4. Like NaxCoO2 it shows a large crystal field gap between narrow t2g and eg manifolds, but because of its stoichiometry is a semiconductor rather than a high carrier density metal.},
doi = {10.1016/j.solidstatesciences.2007.03.008},
journal = {Solid State Sciences},
number = ,
volume = 9,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}